c/5 Orthogonal spaceship

From: coe@vitsemi.com (Tim Coe)
Date: Wed, 31 Jan 96 08:45:59 PST
Subject: An orthogonal c/5 ship

Eight solid weeks of cpu time on a Pentium Pro 133 and an average of 5 Hypersparcs for six weeks have finally resulted in success in my width 9 search for a c/5 symmetric orthogonal ship with dead cells down the middle (actual width 19). The Pentium Pro had the actual honors of spitting the ship out last night.

Source code for my search program is available to anybody who wants it. It now has a usage statement, command line options, and checkpointing. It still has no comments in the main code. The checkpointing format allows fairly easy chopping of a search into multiple pieces through the use of "head" and "tail" and thus distributing the work among multiple CPUs.

Upon reading some of Harold Mackintosh's writing I have learned that my search algorithm can quite precisely be described as being an extender of DeBruijn diagrams. Over the next couple of months I am planning to write up a more complete description of my algorithm.

I've been searchin' so long,

-Tim Coe coe@vitsemi.com

A period 5 spaceship that travels orthoganally at c/5. To the best of my knowledge the first one found. Tim Coe January 31, 1996